It is very likely that The Origin of Chinese Characters is influenced by Huang Di's Inner Classic after investigating the author of The Origin of Chinese Characters and identifying the publishing times of them. The following conclusions are reached through comparing and analyzing thinking modes, philosophical conception, and knowledge of human anatomy, disease and treatment in them: the knowledge of traditional Chinese medicine (TCM) contained in The Origin of Chinese Characters is in direct line of succession with the Inner Classic; the universe and ecomedical thinking modes of "heaven-earth-human being" in The Origin of Chinese Characters and the Inner Classic respectively are cut from the same cloth; the theories of qi, yin-yang, and the five phases, the theoretical foundation of the Inner Classic, can be traced back to their sources through The Origin of Chinese Characters; The Origin of Chinese Characters traces back to characters' origin and original meanings through analyzing their structures, therefore, the book is important for us to study and read the Inner Classic, and to probe into the origin of TCM as well.